Hydraulic jack.



PATENTED APR. 14, 1.901%.

G. APGAR. HYDRAULIC JACK. APPLICATION FILED AUG. 23, 1907.

alien/e1 9 vmmm W UNITED STATES PATENT OFFICE.

*- GEORGE APGAR, OF WHITE HOUSE STATION, NEW JERSEY. I

HYDRAULIC J'ACK.

Specification of Letters Patent.

Patented April 14, 1908.

Application filed August 23, 1907. Serial No. 889,903. To all whom it may concern: packing oove 10 and engaging the inner Be it known that I, GEORGE APGAR, a citizen of the United States, residing at White House Station, in the county of Hunterdon and State of New Jersey, have invented a new and useful Hydraulic Jack, of which the f lowing is a specification.

's invention has reference to improvements in hydraulic j acks, and its ob'ect is to produce .a self-contained hydraulic jack adapted for lifting buildings, railroad tracks, or other structures, more particularly where it is desirable that the fluid contents. of the jack should not be wasted.

, he present invention comprises an inclosed 0 fluid,'in which cha'm-' er is another chamber containing'ainulti le series of plungers which when acted upon by are projected to raise theweight. Also Within the chamber there is a pump operated from the exterior of said chamber, and a manually operated relief valve is provided whereby the fluid pumped into the plunger chamber may be allowed to flow therefrom into the chamber containing the main reservoir, and by thus relieving the pressure the plungers Will gravitate to their initial retracted position.

he invention will be fully understood by reference to the following detailed description, taken in connection with the accomanying drawings forming part of this specication, in whic'h,

Figure 1 is a section on the line m-sc of Fig. 2; and Fig. 2 is a section on the line y'y of Fig. 1. 7

Referring to the drawings, there is shown a closed chamber 1, generally rectangular in shape with rounded corners, and at one side this chamber has an elevated portion 2, the top of which has an opening normall closed by a cover 3 screwed thereinto. crewed into the bottom wall 4 ofthe chamber 1 ably thicker than top walls, is acylinder 5 extending upward to and through the to wall of the chamber 1, where it .is formedhvith an inwardlyrojecting annular flange 6 in which is forme a packing groove 7. Fitting this cylinder is a tubular member 8 having an outwardl -directed annular flange 9 at itslower en provided with a walls of t e cylinder 5, and at its u per end this tube 8 has an inwardly-directe annular flange 11 provided with a packing groove 1-2. Sliding within the tube 8 is still another tube 13, likewise provided witha lower outwardlydirected annular flange 14 having a packing groove 15 and at its upper end with an inwardly-directed annular flange 16 havi a packing groove 17 Within the tubu ar member 13 18 having at its lower end an outwardlydirected annular flange 19 formed with an annular packin groove 20 and at the lower end of the bloc 18 is provided with a central recess 21.

Screwed into the bottom, 4 of the chamber 1 at a point coincident with the elevated portion 2 1s the extended base 22 of a ump cylinder 23 and fitted to this pump cy inder is a cylindrical plunger 24 of the displacement type. The upper end of the plunger is formed with two diametrically opposed extended wings 25 engaging opposed uideways 26 formed on the inner face of t e extension 2. Formed on the top of the ump plunger or piston is a yoke 27 in whic gages the crank end 28 of a rock-arm 29 extending through suitable bearings 30 formed on the side of the casing 1 an exterior to the casing the rock-arm receives an operating lever 31.

On one side of the pump cylinder there is formed a boss 32 through which there is a passage 33 for the inlet of oil from the interior of the casing or chamber 1 to the interior of the ump cylinder 23, and in this passageway t ere may be located a checkvalve 34. Y

Extendin from the bottom of the pump cylinder 23 1s a passage 35 through the bottom 4 of the casing, and this passage opens into the interior of the cylinder 5 through a check-Valve 36 which permits the flow of fluid into the cylinder 5 but prevents its return therefrom.

Mounted upon the flange 22 of the cylinder is a valve casing 37 communicatinlg y a passage 38 with the interior of the cy inder 5, and this passa c has a free outlet at 39 communicating wit casing or chamber 1. A valve stem 40 en the interior of the there slides a cylindrical block p p l .the upper end of the crvllinder 18 are in the lowermost ters this casing and is continued upward same is provided with a handle 41.

Now, let it be supposed that there is a suppl of fluid, preferably oil, contained in the c amber or casing 1, and let'it be also supposed that the various packing grooves in t e several cylinders are properly supplied with acking, rendering the oints oil-tight,

and a so let it be supposed that the valve .the W111 s end of t e latter bein gagement with the wa s of the pump cyliner. On the return stroke of the plunger 24 the valve 34 will close and the oil thereby confined in the cylinder 23 escapes through the passage 35 and by the check-valve 36 into the interior of the cylinder 5. In the normal operation of the device, when it is ready to start, the tubes 8 and 13 and the osition, on the bottom 4 at t e lower t at is, resting end of the cylinder 5.- When fluid enters the cylinder 5 it will tend to lift the several movable parts which were telescoped insaid cylinder and anything englaged by the cylinder 18 will be raised as t e fluid is pumped into the cylinder 5, and the extreme extent of movement of the cylinder 18 will be that of its own range of movement and the added ran e of movement of the tubes 8 and 13.

hen it is desired to relieve the ressure which has been established in the cy 'nder 5 the valve stem 40 is rotated so as to open the passage 38 through the port 39 and the oil which has been pum ed into the cylinder 5 is allowed to escape ack into the main reservoir, bein forced through the passa e 38 by the weig t of the cylinder 18 and tu es 8 and 13.

When it is desirable to dismantle the structure for cleaning or other purposes the cover 3 is removed and the rock shaft 27 is pulled to one side so that its crank end-28 is disconnected from the yoke 27 and out of the path of the pump piston or prlunger. The latter ma now be elevated cm the pump and wit drawn through the opening closed by the cover 3 and, if desirable, the pump cylinder itself may be unscrewed from its seat in the bottom 4.

The cylinder 5 may also be unscrewed from its seat in the bottom 4' and may be lifted out from the casing or chamber 1 through the top thereof, after which the several plungers,

through the cover 3 and exterior to the' consisting of the tubes 8 and 13 and cylinder ,18, may be lifted from the casin rior of the casing is now accessi 1e and ma be easily cleaned after the removal of the oi and the oil may be replaced or fresh oil may be introduced, as desired.

Since the valve controlled by the valve rod 40 may be of very simple nature, this rod may be so constructed as to be readily removed when placed in some redetermined position, so that it may e withdrawn through the cover 3 before the latter is unscrewed from its seat.

When the several liftingplungers are in their lowermost position the recess 21 re- -ceives the valve 36, and in order to facilitate the cleaning of the structure the valve seat 42 of this valve 36 may also be screwed into a suitable nut formed in the bottom 4 around the corresponding end of the passage35.

I claim 1. A hydraulic jack composed of a casin a power cylinder entering t e casing throng the upfper side thereof, and seated inthe bottom 0 the casing, a pump also seated in the bottom of the casing adjacent to the power cylinder, connections between the dump and power-cylinder and formed in the ottom of the casing, a removable valve seated in the bottom of the casing and removable therefrom through the top of the casing, being within and central to the power cylinder and rojecting into said power cylinder, and a teescoping series of plungers adapted to the power cylinder said series of plungers having the innermost one solid "and provided with a central recessat the lowerend to receive said valve, all the plun' ers when retracted resting directly on theii casing. I

2. A hydraulic jack composed of a casing having the bottom and side walls all formed in one piece, a power cylinder removably secured in said casing and extending from the bottom of the casing to and through the top wall thereof, a series of telescoping lungers in the casing, the innermost one bemg solid and being provided with a central recess at its lower end and all-the plungers resting on the bottom of the casing when retracted, a valve removably secured on the upper face of the bottom of the casing con centric with the power cylinder and adapted to enter the recess in the bottom of the innermost plunger when the tracted, a pump cylinder removably secured within the casing to'the bottom thereof, 0 posing guides formed inside the casi ont e walls thereof and spaced apart a, istance greater than the width of the pump cylinder, a pump plunger having integral laterall -extending wings engaging said guides an also provided with an integral yoke, a rook-shaft said valve ottom of the I The 1ntesuitable plungers are re= extending through and journeled in the casmy own, I have hereto afiixed my signature ing and provide with a, crank end extending in the presence of two witnesses. through and engaging the yoke, a removable cover on the casing in line with the pum GEORGE APGAR 5 cylinder, and a relief valve for the power cy Witnesses: inder. LESTER APGAR,

In testimony that I claim the foregoing as NEWTON WYCKOFF. 

